Orhan ÖZTOPRAK, Yılmaz Umut ASLAN, Yasemin KULAK ÖZKAN

Evaluation of laminate veneer preparation depth with 3D systems

Background: Preparation depth of laminate veneers are essential in retention and structural integrity of restorations. The aim of this study was to evaluate the difference between a trained professional prosthodontist (PP) and a postgraduate prosthodontics student (PPS) in the preparation depth of laminate veneers by scanning the tooth with a 3D scanner before and after the preparation. Methods: Twenty extracted human maxillary central incisors were evaluated by a PP and PPS. A 0.5 mm depth guide bur was used in for facial reduction and a 1 mm incisal reduction was performed with a deep chamfer. The teeth were scanned with a laser scanner at an accuracy of 10 µm. The teeth were separated into 3 parts (incisal, middle and cervical) and then 5 points were randomly selected on the unprepared tooth and then lapped over when the preparation had been completed. The data of the difference was calculated in 3D scanning software Magics (Materialise NV, Belgium). Statistical analysis were performed with one-way ANOVA (p < 0.05). Results: PP results showed mean values in the Incisal of 0.328+0.045 mm, Middle of 0.375+0.097 mm and Cervical of 0.471+0.07 mm. PPS results showed mean values in the Incisal of 0.323+0.056 mm, Middle results of 0.403+0.083 mm and Cervical results of 0.462+0.075 mm. Conclusion: These results suggest that a PP or a PPS can both achieve the same precision in the preparation using a depth guide bur.

Lamina veneer preparasyon derinliklerinin 3B sistemler ile değerlendirilmes

Amaç: Lamina veneer restorasyonlarında preparasyon derinliği, yapısal sağlamlığın ve tutuculuğun sağlanmasında temel faktörlerin başında gelir. Bu çalışmanın amacı, deneyimli bir prostodontist (PP) ve yüksek lisans protodonti öğrencisinin (PPS) lamina preparasyon derinliklerinin, preparasyon öncesinde ve sonrasında 3B tarayıcı ile farklılıklarının değerlendirilmesidir. Gereç ve yöntemler: PP ve PPS 20 adet çekilmiş insan maksiller santral kesiciyi değerlendirmiştir. Fasiyel preparasyon için 0,5 mm’lik derinlik rehberli frez kullanılmıştır. İnsizal preparasyon için ise 1 mm’lik champher frez kullanılmıştır. Dişler, 10 µm hassasiyetinde lazer tarayıcı ile taranmıştır. Dişler 3 kısıma (insizal, orta ve servikal) bölünmüş ve 5 noktadan incelenmiştir. Preparasyon yapılmamış ve yapılmış dişler üst üste çakıştırılarak Magics (Materialise NV, Belgium) 3B tarama yazılımında aralarındaki farklar incelenmiştir. İstatistiksel analiz tek yünlü ANOVA ile yapılmıştır (p < 0.05). Bulgular: PP sonuçları ortalama insizalde 0.328+0.045 mm, ortada 0.375+0.097 mm, servikalde ise 0.471+0.07 mm olurken, PPS sonuçları ortalama insizalde 0.323+0.056 mm, ortada 0.403+0.083 mm ve servikalde 0.462+0.075 mm olarak bulunmuştur. Sonuç: Bu sonuçlar, derinlik belirleyici frez kullanıldığında PP ve PPS benzer preparasyon hassasiyet gösterdiğini belirtmektedir.

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